This invention relates to visual aids for the visual handicapped and, more particularly, to an adjustable telescope alignment apparatus to enable handicapped users to optimumly adjust the telescopic aid according to their preferences.
There are many people throughout the world who suffer from various visual handicaps. Many such people have extremely limited fields of view and have extremely poor eyesight. These defects are due to many different diseases or different types of eye degeneration. For example, many people in the United States suffer from macular degeneration. Age-related macular degeneration is a leading cause of visual loss in the United States in adults who are sixty years of age and older. It is estimated that over 150,000 people develop this disease each year. Macular degeneration is manifested and defined by two different types of conditions. The first is known as atropic or "dry" type which results in a gradual atrophy of the sensory retina and the pigment epithelium. The second type is referred to as the exudative or "wet" form. In this type, new vessels proliferate from the choriocapillaris under the sensory retina which produce hemorrhaging and scarring. This type of macular degeneration may be treated by laser photocoagulation provided that the neovascular tissue is outside the foveal avascular zone. Thus, patients who have lost vision due to macular degeneration can be helped by optical aids such as telescopic assemblies that magnify an object to be viewed. Various other persons with visual defects also require telescopic assemblies. These people, for example, are those who suffer from glaucoma, detached retinas and other similar visual defects. In order to accommodate such defects, many patients are required to wear telescopic aids as noted above. These telescopic aids, for example, are Galilean telescopes which are designed for distance tasks. Certain tasks have to be performed when the patient is stationary and others when the patient is mobile. Such telescopes are conventionally carried in plastic or glass carrier lenses. The patient's visual prescription can be incorporated into the carrier lens or not. In any event, such telescopic units can be supplied with many different types of housings to accommodate many different individuals and defects. The telescopes are mounted in a chosen location of the carrier lens which may, for example, be the vertical center. The telescopes are positioned according to the patient's interpupillary distance (p.d.) Any position within the physical limits of the carrier lens can be specially requested. The telescopes are normally mounted in a straight ahead position and require extensive fittings as well as extensive adjustments by the practitioner. Other telescope devices are referred to as bioptic telescopes and these are mounted high in the carrier lens so that the telescope would be out of the way when the patient is moving about or doing general work. In this particular instance, the carrier lens of the patient contains the patient's normal distance prescription. The telescopes are mounted high in the lens so that they can be utilized only when the patient desires to use them. The patient's distance prescription can be incorporated into either the telescope, the carrier lens or both. It is usually recommended that the prescription be accommodated in both. As indicated, the bioptic telescopes are generally mounted in the carrier lens such that the optic center of the ocular lens is below the top of the carrier lens. They are laterally decentered to the patient's p.d. and have a standard drilling angle of inclination of ten degrees upward from the horizontal plane. Any position or angle can be specially ordered. There are also telescopes designated as spiral expanded field prism telescopes which allow the patient full flexibility and which are capable of being adjusted. These telescopes can be mounted in a plurality of different ways and are also accommodated by the carrier lens. As one can understand, the mounting of telescopes within a carrier lens is an extremely difficult procedure. There are, for example, telescopes which are universally adjustable and can be therefore operated or oriented in all three planes. Such telescopes are mounted in a carrier lens as accommodated by a spectacle frame. See, for example, U.S. Pat. No. 4,863,468 entitled UNIVERSALLY ADJUSTABLE TELESCOPIC SPECTACLE ASSEMBLY FOR USE WITH IMPLANTED INTRAOCULAR LENSES AND ASSOCIATED METHODS issued on Sep. 5, 1989 to Richard E. Feinbloom, et al, and assigned to Designs for Vision, Inc., the assignee herein. That patent describes a universally adjustable telescopic spectacle assembly for use with an implanted intraocular lens. The assembly employs an objective lens which has positioned in front of it a cylindrical lens to provide cylindrical correction to the handicapped user. The telescope assembly employs universal motion in that the assembly can be moved with respect to the spectacle frame so that one is able to shift the objective lens axis about a central point while further having the capability of moving the objective lens in a spiral motion away from or towards the eye of the user. The assembly has a pivotal joint mechanism to permit maximum oblique adjustment of the entire telescopic assembly as related to the optical or central axis of the objective lens. In this manner, a change in the condition of vision or misalignment of the intraocular lens as inserted during surgery can be compensated for by the universal adjustable telescopic lens assembly. Apart from the device described in the above-noted patent, telescopes are generally fitted by a practitioner working closely with the patient. After a satisfactory fitting, the practitioner then prescribes to the laboratory where the telescope assembly is to be positioned with respect to the carrier lenses or with respect to the spectacle frame. The laboratory provides a frame according to the prescription of the practitioner as selected by the patient. The laboratory drills the holes in the carrier lenses at the proper position and angle to tilt the telescope in the proper direction as prescribed by the practitioner. In any event, when the spectacles are returned to the practitioner and tried on the patient, there is a great deal of difficulty in attempting to accommodate the spectacle arrangement with the patient's preferences. Since the telescopes are firmly secured to the frame, they cannot be conventionally adjusted and hence one has to adjust the spectacle frame to accommodate a proper orientation of the spectacles. The frame has to be adjusted including all aspects such as the nose pads, the temples, to satisfy the proper panascopic and retroscopic tilt. The above-noted patent permits universal adjustment of a telescope assembly and such a device has extreme advantages as explained in that patent.
It is an object of the present invention to provide an adjustable alignment apparatus for a telescope which is simple to fabricate and which enables a patient as well as a practitioner to adjust the telescope assembly with minimum difficulty and with great ease.
It is a further feature of the present invention to provide an adjustable telescope assembly whereby a user or a practitioner can adjust the telescope within a desired cone of rotation and then lock the assembly in an optimumly adjusted position.